Vacuum-pump



No. 472,802. -PatentedAprQ1Z, 1892.

ll-l fa lA/I/E/VTOR 1 ATTORNEYS- UNITED STATES" PATENT OFFICE.

JOHN PHILIP BOETTIGER, OF GOLD SPRING, NEW YORK.

VACUUM-PUMP.

SPECIFICATION forming part of Letters Patent No. 472,802, dated April 12, 1892.

Application filed October 7, 1891. Serial No. 407,973- (No model.)

To all whom it may concern.-

Be it known that I, J OHN PHILIP BOE'ITIGER, a citizen of the German Empire, residing at Cold Spring, in the county of Putnam and State of New York, have invented certain new and useful Improvements in Vacuum Pumps, of which the following is a specification.

This invention relates to pumps for the exhaustion or compression of gases and other elastic fluids; and the object of the invention is to compensate the pressure in the spaces of tightly to the inner surface of the guide-cylinder and that is connected by a web with the contracted portion of the slide-valve, said ring or band opening or closing the suctionport as the slide-Valve moves in one or the opposite direction. The contracted portion of the slide-valve is made of such length that it connects the ports of the pump-cylinder when the piston arrives at its dead-point position, so that the pressure of the gases in the'deadspaces of the pump-cylinder is compensated by means of the induction and eduction channels and the annular space at the center of the slide-valve, while at the same time the suction-port is closed by the split ring or band, as will be more fully described hereinafter, and finally pointed out in the claims.

In the accompanying drawings, Figure 1 represents a vertical longitudinal section of my improved valve for pumps for moving gaseous bodies. Fig. 2 is a vertical transverse section of the same on line 2 2, Fig. 1 and Fig. 3 is a horizontal section on line 3 3, Fig. 1.

Similar letters of reference indicate corre sponding' parts in all the figures.

Referring to the drawings, A represents a pump-cylinder, which is provided with the usual induction and eduction channels a a.

the heads of the valve-chest and the ends of the guide-cylinder are connected by a longitudinal connecting-channel d with a delivery-port d In the guide-cylinder C is arranged a cylindrical slide-valve D, which is open at the ends and is provided with a central contracted portion D, said ends being closed by spring-cushioned delivery-valves D that are alternately operated by a longitudinal spindle d, which is supported in fixed center bearings of the slide-valve D and held in position thereon by means of suitable screw-nuts (1*. The spindle d of the slidewalve D extends into central sockets e of'said valves, which sockets extend into sockets 6 located in the heads of the valve-chest, as shown clearly in Fig. 1.

The slide-valve D is operated by means of two rods f, which are attached at two diametrically-opposite points to the slide-valve D and guided in stuffing-boxes applied to the head of the valve-chest, said rods being connected at their outer ends by a cross-head f, which is again attached to a valve-rod f by which the connection with the operating element of the pump-actuating motor is made. The central contracted portion D of the slidevalve D is made of such a length that it extends over the ports of the induction and eduction channels, but without entirely closing the same when the piston arrives at one of its dead-point positions, so that the pressure in the dead-space formed at one end of the same can be compensated by connection with the dead-space at the opposite side of the same. In this position of the slide-valve D'it is necessary to close the suction-port b, which is produced by providing the contracted portion D with a split ring or band D that is connected by a web w with the contracted portion, as shown clearly in Figs. 1 and 2. The split ring or band D fits tightly to the inner surface of the guide-cylinder O and produces the closing of the suction-port b, when the compensating action between the dead-space of the pumpcylinder takes place. As soon asthe slide valve D is moved in one direction the suctionport 6 is opened, so that the air orthe gases can be drawn by the piston into the cylinder, while the air or the gas that is at the time in the cylinder is forced through the eductionchannel into the cylinder-valve D and through the delivery-valve D at the corresponding end of the slide-valve into the delivery-channel d and to. the delivery-port d The slidevalve D is provided atits bottom with ports 9 g, by which the connection with the induction and eduction channels a a is made. When the piston arrives at its dead-point position at the opposite end of thepump-cylinder, the compensatingaction takes place "for a short time through the channel a and the contracted portion of the slide-valveD,-While' during the same the-suction-port b is closed bythe split ring or band E. As soon as the piston changes its direction of motionthe air orthe gaseous body in the cylinder is forced through the opposite channel of the cylinder and the corresponding port of the slide-valve into the latter and delivered by the opening of the delivery-valve to the delivery-channel at the! opposite end of the-valve-chest, and thence to the delivery-port, as customary in pumps'of The lap of the slide-valve over the induction and ed uction 'ports of thepump cylinder and the split ring or band that is this. class.

connected with the contracted portion of the slide-valve forms the novel features of my invention, as the remaining accessoriessuch as the spring-cushioned delivery-valves, the guide-spindle, and the oil packing of thepis-- ton-rod of the pump-cylinder-are well'known.

My improved valve is applicable to vac-' uum-pumps and all other pumps in which.

gaseous bodies have to be moved. It is also applicable to air-compressors and blowing-engines, in which, however, the pressure is not produced by the suction but by the compression of the air orgaseous body. In every application of the slide-valve, however, an equiformed around the middle contracted portion of the slide-valve, which annular space is connect'ed for a short time by the induction and ieduction ports with the dead space of the cylinder and with the delivery-port of the valvechest, While the suction or inlet port is closed for the time when the pressure is compensated by the split-ring arranged at the contracted portion of the slidevalve.

Having thus described myinvention, whatI claim as new, and desire to secure by Letters Patent, is

1. The combination of a pump-cylinder having induction and educti-on ports, avalvechest, a guide-cylinder in said valve-chest,

provided with a lateral suction-port, and delivery-channels in the bottom of the guidecylinder, a slide-valve guided in said cylinder, spring cushioned delivery valves arranged at the ends of the slide-valve, a contracted portion at the central portionof the slide-valve, said contracted portion being'arranged to lap over the induction and ed'uct'ion ports of the pump-cylinder-when the piston arrives at one of its dead-pointpositions, and a split ring orband 1 connected with the contracted portion of the slide-valve, so as to keep the suction-port closed while the compensation of pressure between the deadwith the'ends of the guide-cylinder and the Cdelivery-porhand a split ring that is connected by a web with thecontracted portion of theaslidewalve and adapted to close the suction-port when the piston arrives at oneof its-dead-point positions, so that the annular space formed by the contracted portion can beused for compensating the pressure in the cylinder at the opposite sides of the piston, substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name inthe presenceof two subscribing witnesses.

JOHN PHILIP BOETTIGERr Witn esses PAUL GoEPnL, CHARLES SCHROEDER. 

